Due to the western lifestyle, correlated with a high calorie intake and low physical activity, obesity is becoming a major health problem. All over the world obesity reaches epidemic proportions. Obesity is closely linked to type 2 diabetes, a multi-factorial disease that increases the presence of multiple health problems. Until now, exercise and dietary intervention seem to be the single most effective interventions to treat obesity and type 2 diabetes mellitus. In obesity and type 2 diabetes, not only fat accumulation in adipose tissue, but also fat accumulation in the peripheral tissues occurs. Fat accumulation in peripheral tissues has been associated with insulin resistance. Exercise seems to have a positive effect on the accumulation of fat in the peripheral tissue and on the insulin sensitivity in type 2 diabetic patients.